427 build thoughts
New motor:
LSR Block, 427ci
Callies 8 cw Crank
Callies Extreme rods 4" stroke
Carillo 4.125 pistons (BLS1204-STD)
Mahle ring pack
Cam is a 250/264, 710/700 on a 113
Johnson ST2116LSR lifters (pre load set at .028 intake and .030 exhaust)
CT Porting CID LS7 with a 52cc chamber, 7mm valve stems (Titanium intakes still).
Static is around 14-14.5:1
Ironmask Maximus SR MSD with 112 tb
Pump E85
New motor:
LSR Block, 427ci
Callies 8 cw Crank
Callies Extreme rods 4" stroke
Carillo 4.125 pistons (BLS1204-STD)
Mahle ring pack
Cam is a 250/264, 710/700 on a 113
Johnson ST2116LSR lifters (pre load set at .028 intake and .030 exhaust)
CT Porting CID LS7 with a 52cc chamber, 7mm valve stems (Titanium intakes still).
Static is around 14-14.5:1
Ironmask Maximus SR MSD with 112 tb
Pump E85
Did some intake manifold testing today on the LS7-based combo.
Here’s the setup:
Factory LS7 block, crank, and titanium rods with ARP bolts
JE drop-in pistons (thermal barrier crown + skirt coatings), 1.2/1.2/3mm ring pack
Factory LS7 heads with my CNC port program
Factory Ti intake valves, stainless exhausts, dual spring kit with Ti retainers
Texas Speed roller tip rockers, 3/8” .080” wall pushrods
Comp Cams EVO hydraulic roller lifters
Custom cam: 24x/25x, .7xx” lift, 113.5 LSA, straight up — no advance
Factory LS7 pump, ARE dry sump pan
11:1 compression, heads cleaned up .005”, flat tops with valve reliefs
Intake Manifold Testing Results:
Intake 1: Holley Hi-Ram
Peak Torque: 631.8 lb-ft @ 5200 RPM
Peak HP: 754.5 @ 7300 RPM
BSFC: .468 at peak power
RPM spread (TQ–HP): 2000 RPM
Intake 2: TSP Titan w/ twin 4150 throttle bodies
Peak Torque: 632.7 lb-ft @ 5600 RPM
Peak HP: 764 @ 7400 RPM (highest of the test)
BSFC: .489
RPM spread (TQ–HP): 1800 RPM
Intake 3: Iron Mask Maximus (MSD style)
Peak Torque: 653 lb-ft @ 5000 RPM (highest of the test)
Peak HP: 754.2 @ 7200 RPM
BSFC: .430 (best of the test)
RPM spread (TQ–HP): 2200 RPM
I would expect something with more compression, CID heads, more cam etc.. to make ~730 STD on Pump E with a BTR manifold.
I would expect something with more compression, CID heads, more cam etc.. to make ~730 STD on Pump E with a BTR manifold.
https://youtu.be/EYs3vXhCleE?si=FXMrumpuwGvRbRCT
I have a similar setup, ported heads, my cam is slightly bigger than the RPM B3, I just put a BTR Trinity on today and it's certainly not making 690 whp on most dynos. It runs great but I'm waiting for my Maximus 112SR to be done and I fully expect the Maximus to outperform the Trinity from top to bottom.
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maybe just a tad, but unless he is changing intakes, i wouldn't put much into stock into the cam waking the engine up drastically. the maximus is great, but it still only makes good power to 7200ish. no point in camming the engine for higher rpm if the intake won't let it happen. If i was going to do mine again, i'd actually probably take a couple more degrees out of the intake side now that i have the data.
Another reason not to get crazy with the cam's intake duration.. The MSD won't like shifted above 7500. It falls off too hard to justify spinning it that high. Every single pass i made last year shifting above 7500 et'd and mph'd slower than shifting 7200-7500. the exception are my 60-130 pulls, shifting once from 2-3 and taking 3rd to 8192 was always faster than shifting a second time since 130 happens in an awkward spot for me. either way, my point is that if he is going to make a significant cam change, it should be in conjunction with a computer change for more RPM and a square root fab/shearer hi-ram combo.
The Maximus is a badass piece for sure. And nice it doesn’t heat soak like the others.
I have a similar setup, ported heads, my cam is slightly bigger than the RPM B3, I just put a BTR Trinity on today and it's certainly not making 690 whp on most dynos. It runs great but I'm waiting for my Maximus 112SR to be done and I fully expect the Maximus to outperform the Trinity from top to bottom.
Do you have proof of this?
I'm also certain that my car is not making anywhere close to 690 whp with my BTR Trinity. I have the V1 runners not the V2 runners, but I really doubt the V1 runners are going to be down 60 hp compared to the V2 runners. The other day on Facebook, Brian Tooley told someone with a 1000 whp setup that he might pick up 20 hp switching from V1 runners to V2 runners. Probably more like 10-12 on a heads/cam LS7 I would imagine.
I'm also certain that my car is not making anywhere close to 690 whp with my BTR Trinity. I have the V1 runners not the V2 runners, but I really doubt the V1 runners are going to be down 60 hp compared to the V2 runners. The other day on Facebook, Brian Tooley told someone with a 1000 whp setup that he might pick up 20 hp switching from V1 runners to V2 runners. Probably more like 10-12 on a heads/cam LS7 I would imagine.








